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With their high elasticity and viscosity, calcium hydroxylapatite (CaHA) fillers are now widely used to treat age-related or hereditary facial soft tissue volume deficits. CaHA filler volume augmentation is further enhanced by its ability to stimulate neocollagenesis and improve skin quality. However, its high viscosity and cohesivity may hinder its spread and distribution, while its injection by cannula or needle may require moderate extrusion force and lead to uneven distribution or focal accumulation in tissues. Thus, new or modified delivery techniques and tools have emerged, particularly from East Asian physicians. One such technique is hyperdilution with diluents such as lidocaine or normal saline. CaHA hyperdilution appears to be more frequently used by experienced injectors who have varying methodologies. Here, we demonstrate the precise delivery of diluted filler to treat indications related to hereditary volume deficits, volume loss, or aging in the periorbital, nasolabial and submalar regions, marionette lines, and hollowed mid-facial areas. Regardless of age or indication, dilution eases filler delivery for the injector, while using lidocaine as the diluent decreases patient discomfort and minimizes pain. Increasing injection diluent volumes reduces filler thickness (viscosity) and facilitates its even spread, encouraging skin stimulation through more direct contact with tissues and minimizing unevenness. Our results effectively demonstrate that hyperdilution is an innovative and positive evolution in CaHA filler delivery.
Background: Acne during youth can leave permanent facial scarring. The depressed acne scars can be treated by injection of stabilized hyaluronic acid (S-HA) into the dermis. Due to the large number of acne scars, manual injection methods are technically difficult and bear high risk of lump formation in the dermis. Therefore, the author designed a specific injection method to solve the two abovementioned problems. Aims: This research aims to assess the effect of the intradermal injection of S-HA and aboborulinumtoxinA mixture in the treatment of all types of acne scars. Materials/Methods: A total of 102 patients who suffered from acne scars were treated with a mixture of S-HA (Restylane Vital®) and abobotulinumtoxinA (Dysport ®). Using an automatic injector, micro-droplets of the mixture (0.001 cc of S-HA and 0.125 U abobotulinumtoxinA) were delivered into 1000 intradermal sites on whole face except eyelids. This instrument radically reduced injection amounts per site (0.001 cc), lessened manual operator efforts, and ensured consistent injection depth (from 0.8 to 1.2 mm depending on individual dermal thickness) into the facial dermis. The changes in each depression site of acne scars were evaluated by topographic computer analysis (point roughness), based on the 40 magnification microscopic photographs generated. Depth measurements of each small acne scar point were taken one by one at the exact same point before and after the treatments. Global Aesthetic Improvement Scale (GAIS) was measured for improvement of acne scars at 1-and 6-month posttreatment. Additionally, serial histologic examinations of the biopsy specimens evaluated neocollagenesis, neoelastinogenesis, and longevity state of the S-HA. Results: A total of 78 patients showed improvements of depressed acne scars in physical examinations, medical photographs, and dermascopic photographs. Using topographic computer analysis, the average point roughness decreased 27.48% (at 1 month) from 29.042 ± 6.85 (baseline) to 21.05 ± 6.30 µm (P < .0001), corresponding with scar improvements observed in physical examinations, and 3.02 ± 0.66 of GAIS at 1-month posttreatment. Using an injector allowed the hydrotoxin mixture This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
PCL filler can be injected in two major ways to control pain. One such method involves mixing 0.3cc of PCL filler with lidocaine, and the other is the method introduced in this report, which involves pre-injection with a tumescent solution. It is hard to reduce pain effectively with pre-mixing PCL filler with lidocaine because there may be not enough time to act lidocaine solution effect immediately for pain control. The pre-mixing method changes the properties of the original filler, especially the property of the CMC portion. Therefore, in my simple and novel technique, tumescent solution is injected, followed by PCL filler which preserves the original CMC property. This is done after sedation of the tissue by the tumescent solution and dissection of soft tissue to create a space for the ensuing PCL injection. After pre-injection with tumescent solution, histological analysis indicated that the tissue did not become irritated in response to the foreign body material (PCL filler) or the mechanical trauma caused by the needle. That is the key mechanism of the tumescent injection method for reducing tissue reaction and that may reduce pain and swelling during and after PCL filler injections.
Background: Polycaprolactone (PCL) implants show isovolemic degradation during phase-1 degradation; they maintain their volume as their molecular weight decreases. Phase-2 begins with PLC volume being reduced by bulk degradation with autocatalysis. Isovolemic degradation of PCL particles during phase 1 and their longevity should be established in humans. PCL particle size can be mathematically calculated through cross-sectioned PCL particles in biopsy slides. Methods: Biopsy specimens were obtained from humans after giving them a subdermal injection for 4 years to measure cross-section diameters of PCL particles. In all (160) biopsy slides, all cross-sections of PCL particles were measured in size in microscopic photographs, and the real size of PCL particles was calculated through Equation of a circle (Equation circle ) and mean value theorem for integrals (Integral Theorem ). Diameters of Ellansé particles were measured with particle size analyzer. Results: On average, the calculated PCL particle size using Integral Theorem was 42.83 (immediately), then 43.18(1), 42.62(2), 40.90(3), and 34.46 µm(4 years), respectively. These results were similar to the diameters calculated using the Equation circle . PCL size remained unchanged until 3 years, which began to decrease from the fourth year, making the transition point in between. In particle size analyzer, the mean diameter was 42.42 µm. Conclusions: PCL particle size was mathematically calculated for 4 years in an in vivo biopsy study. Until 3 years after the injection, PCL particle diameter remained at 95.47% and showed phase-1 isovolemic degradation. From 4 years after the injection, particles decreased in size, showing phase-2 bulk degradation. PCL particles were smooth and circular for 3 years, and from the fourth year, the surface became very rough. The Ellansé-M longevity was longer than 4 years.
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